There are a few things you need in order to make a car couch. The first is some fabric, and the second is some screws. You will also need a drill and a saw. To begin, take the fabric and cut it into pieces that are about twice the size of your car. Make sure that each piece is cut so that it covers the entire back of your car. Next, drill two holes in each piece of fabric and then screw them together using screws that have been provided. Finally, use a saw to cut out the desired shape for your car couch.